The overall objective of this proposal is to establish a network site in Denver, Colorado for participation in the Pediatric Pharmacology Research Unit (PPRU) Network. The Denver site will be a collaborative program centered at the National Jewish Medical and Research Center in collaboration with The Children's Hospital of Denver. National Jewish is a world-renowned immunology and respiratory disease center with a strong local, regional and national referral base. The Children's Hospital of Denver, as the Department of Pediatrics for the the University of Colorado Health Sciences Center, has a full complement of academic-based pediatric specialties and is a strong local and regional referral center for a comprehensive program of pediatric medical disorders. Combined these two sites have over 200,000 outpatient clinic visits per year, over 150 daily inpatient admissions, and over 150 beds for inpatient admissions with ready access to patients in network outpatient clinics and pediatric practices in the community. The Principal Investigator for this program will be Stanley J. Szefler, M.D., a physician trained in pharmacy, pediatrics, clinical pharmacology, and allergy/immunology, who has developed expertise in clinical investigations related to therapeutic intervention in childhood asthma and other childhood diseases. Asthma therapy is an area of need identified in recent discussions regarding new legislation for improved information on medications used in children. New developments point to benefits of early intervention with inhaled glucocorticoids identified as preferred medication to prevent irreversible airway remodeling. There is a critical need to establish safety of these medications for optimal application. Collaborators at National Jewish and The Children's Hospital of Denver will contribute expertise based on accomplishments in childhood asthma, immune deficiency, cystic fibrosis, AIDS, neonatal respiratory disorders, diabetes, sickle cell disease, and pediatric oncology. The Denver site will therefore add strength to the PPRU Network in pharmacology research on respiratory, immune deficiency, and infectious diseases. The PPRU, in turn, will contribute expertise in molecular pharmacology, drug metabolism, pharmacokinetics and pharmacogenetics to advance the management of these disorders.